Johns Island weather, tides and hurricane watch
Current conditions from the weather station on the island, the National Weather Service forecast and alerts, NOAA tide times, and the island's climate month by month.
Weather alerts for Johns Island
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At Charleston Executive Airport (KJZI), on the island
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Tides
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NOAA predictions, in feet above mean lower low water. Full tide table at NOAA
Seven-day forecast
National Weather Service, Charleston office
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Hurricane watch
Atlantic hurricane season runs June 1 to Nov. 30.
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Johns Island has a humid subtropical climate. NOAA's 1991–2020 normals for Charleston International Airport, about 14 miles north, put average highs at 91.3°F in July and average lows at 38.9°F in January, with 52.51 inches of rain a year. Hurricane season runs June 1 to Nov. 30.
Key facts
- Hottest month
- July: average high 91.3°F
- Coldest month
- January: average low 38.9°F
- Wettest month
- August: 6.97 in. of rain
- Driest month
- November: 2.66 in. of rain
- Rain per year
- 52.51 in.
- Weather station on the island
- Charleston Executive Airport (KJZI)
- Tide station
- Johns Island, Church Creek (NOAA 8666101)
- Hurricane season
- June 1 to Nov. 30
- Evacuation zone
- Zone B (2026 state plan)
Climate figures are NOAA's 1991–2020 normals, checked Oct 29, 2026.
Johns Island weather by month
NOAA publishes official 30-year averages, called climate normals, for Charleston International Airport, about 14 miles north of the island. They're the standard long-term reference for the Charleston area.
| Month | Average high | Average low | Average rain |
|---|---|---|---|
| January | 60.2°F | 38.9°F | 3.37 in. |
| February | 63.8°F | 41.6°F | 3.05 in. |
| March | 70.1°F | 47.3°F | 3.35 in. |
| April | 77.1°F | 54.5°F | 3.29 in. |
| May | 83.6°F | 63°F | 3.32 in. |
| June | 88.5°F | 70.4°F | 6.21 in. |
| July | 91.3°F | 73.7°F | 6.60 in. |
| August | 89.8°F | 73.1°F | 6.97 in. |
| September | 85.4°F | 68.3°F | 6.01 in. |
| October | 77.9°F | 57.7°F | 4.33 in. |
| November | 69.4°F | 47.1°F | 2.66 in. |
| December | 62.7°F | 41.6°F | 3.35 in. |
| Year | 76.7°F | 56.4°F | 52.51 in. |
What each season is like
- Summer (June–August): average highs of 88.5–91.3°F and the year's heaviest rain, more than 6 inches a month.
- Fall (September–November): September is still hot and wet (85.4°F,6.01 inches). By November, highs average 69.4°F, and it's the driest month of the year at 2.66 inches.
- Winter (December–February): highs of 60.2–63.8°F and lows around 38.9–41.6°F.
- Spring (March–May): highs climb from 70.1°F to 83.6°F, with about 3.3 inches of rain a month.
How tides work around Johns Island
NOAA's tide stations around Johns Island are subordinate stations. NOAA calculates their tides from itsCharleston Harbor station (8665530), shifting the times and scaling the heights for each location:
| Station | High tide vs. Charleston Harbor | Low tide vs. Charleston Harbor | Height factor (high / low) |
|---|---|---|---|
| Johns Island, Church Creek (8666101) | 1 hr 43 min later | 1 hr later | ×1.30 / ×1.16 |
| Limehouse Bridge, Stono River (8665475) | 1 hr 43 min later | 1 hr 34 min later | ×1.08 / ×1.08 |
| Kiawah Bridge, Kiawah River (8667062) | 14 min later | 6 min later | ×1.07 / ×0.89 |
| Rockville, Bohicket Creek (8667089) | 19 min later | 7 min later | ×1.09 / ×1.11 |
That means high tide at Church Creek comes about 1 hr 43 min after Charleston Harbor's and runs about 30% higher. Heights are measured from mean lower low water (MLLW), the average of each day's lower low tide, which is why low tides sometimes read below zero.
Does Johns Island flood at high tide?
Low spots along shorelines and tidal creeks can flood during the highest tides. When that's expected, the National Weather Service in Charleston issues a Coastal Flood Advisory, and it appears at the top of this page while it's in effect. For storm flooding and FEMA flood zones, see ourhurricane guide.
Hurricane season
The Atlantic hurricane season runs June 1 to Nov. 30. Under South Carolina's 2026 hurricane plan, Johns Island is in evacuation Zone B. Our hurricane guide covers the route off the island, emergency alerts and shelters.
Frequently asked questions
What is the weather like on Johns Island, SC?
Hot, humid summers and mild winters. NOAA's 1991–2020 normals for Charleston International Airport put July's average high at 91.3°F and January's average low at 38.9°F. A typical year brings 52.51 inches of rain, and the wettest months are June through September.
What is the best time of year to visit Johns Island?
For warm weather without summer's heat and heavy rain, aim for April and May or October and November. Average highs run 77.1–83.6°F in spring and 69.4–77.9°F in fall, and those months average 2.66–4.33 inches of rain, against about 6 to 7 inches a month from June to August.
Where can I find tide times for Johns Island?
NOAA predicts tides for Johns Island at its Church Creek station (8666101) and at the Limehouse Bridge, Kiawah River Bridge and Rockville stations nearby. This page shows the next high and low tide for each, straight from NOAA.
How do Johns Island tides compare with Charleston Harbor?
They come later and run higher. NOAA calculates Johns Island tides from its Charleston Harbor station. At Church Creek, high tide arrives about 1 hr 43 min after Charleston Harbor's, and high tides run about 30% higher.
Does Johns Island flood at high tide?
Low spots along shorelines and tidal creeks can flood during the highest tides. When that is expected, the National Weather Service in Charleston issues a Coastal Flood Advisory, which this page shows at the top while it is in effect.
Where is the closest weather station to Johns Island?
Charleston Executive Airport (KJZI), on the island itself. The National Weather Service lists it as the nearest observation station for the Johns Island forecast area, and this page shows its latest reading.
When is hurricane season on Johns Island?
The Atlantic hurricane season runs June 1 through Nov. 30. Under South Carolina's 2026 hurricane plan, Johns Island is in evacuation Zone B.
Sources
- Forecast for Johns Island, National Weather Service
- Forecast grid CHS 83,73, alerts and KJZI observations (API), National Weather Service
- Tide predictions: Johns Island, Church Creek (8666101), NOAA Tides & Currents
- Tide prediction offsets for Church Creek, NOAA Tides & Currents
- Charleston Harbor station (8665530), NOAA Tides & Currents
- U.S. Climate Normals, 1991–2020, NOAA National Centers for Environmental Information
- Monthly normals for Charleston International Airport (USW00013880), NOAA NCEI data service
- Atlantic 7-day tropical weather outlook, National Hurricane Center
- Tropical cyclone climatology, National Hurricane Center
- 2026 Hurricane Plan, Annex C: Evacuation zones, SC Emergency Management Division
Live forecasts, alerts and tide predictions load in your browser straight from those agencies each time you open the page.